EP0988894A2 - Vane wheel arrangement for air current roller mills - Google Patents

Abstract

Guide vanes (4) of the mill are rotatable and lockable at a predetermined angle ( alpha ). The guide vanes are attached to the outer ring (2) in the region of the pivot points (25). The outer ring, at least in the swivel areas of the individual vanes, is constructed plane and perpendicular to the guide vanes. The blade ring is constructed as a polygonal ring in segmented form which has a number of segments each with one or more pivotable guide vanes.

Description

The invention relates to a blade ring for airflow roller mills according to the preamble of claim 1.

Airflow roller mills, bowl mills or vertical airflow mills have arranged on a rotatable grinding bowl and grinding rollers rotatable about a fixed axis on. Between the grinding bowl and the mill housing an annular space is formed, in which essentially radially aligned guide vanes for guiding an ascending Carrier gas flow, e.g. an air flow with which the ground good is a sifter is fed. The annular space is designed as a circular ring and is with the guide vanes arranged therein as Blade ring, sometimes referred to as a nozzle ring.

Known blade rings each consist of a rolled one cylindrical or conical outer ring and inner ring or from a combination of a conical exterior or Inner ring and a cylindrical inner or outer ring, between which the guide vanes are arranged. The Guide vanes form flow channels, which are usually have a rectangular cross section.

In addition to these made from rolled rings and welded guide vanes Existing shovel rings are also shovel rings known as a cast construction.

The known blade rings are relatively expensive to manufacture connected. With large roller mills, which Blade rings can have an outer diameter of up to 7 m, are also difficult to transport and assemble master and complex. It is known the shovel rings therefore segment and the individual segments or assemble circular ring sectors on site. The segmentation however requires an annealing treatment so that the Ring construction is relaxed and separating cuts to manufacture no deformation, especially none of the segments Jump up, evoke. Another disadvantage of the known Blade rings is that an optimization of the Grinding and classifying process over the flow direction of the Fluid introduced into the grinding chamber via the blade ring and the two-phase mixture fed to a classifier the fluid and the regrind particles without removing the blade ring and installation of a blade ring with a modified The individual guide vanes cannot be inclined is.

In a blade ring known from DE 34 18 196 A1 the flow conditions during mill operation changed by adjustable outer ring segments. The guide vanes are firm and with an unchanged Tilt angle attached to the inner ring or inner ring segments and protrude between end guide and fastening parts outward. The horizontally adjustable Outer ring segments are sufficient for a maximum cross section the flow channels up to the mill housing and at one minimized cross-section up to the guide vanes. Disadvantageous is affected by the adjustment of the outer ring segments conditional free annular space of the blade ring, through which the fluid flow is unaffected by the inclination the guide panels are flowing.

Another disadvantage is the side guide and Fasteners, which are an outer ring segment and inner ring segment limit and disruptive covers of the blade cross-section represent.

The invention has for its object to provide a blade ring for airflow roller mills and comparable mills, which allows optimization of the grinding and classifying process, in particular during the operation of the mill, with a relatively simple structural design.

According to the invention the object is achieved by the features of the claim 1 solved. Practical and advantageous configurations are in the dependent claims and in the description of the figures contain.

A basic idea of the invention is a blade ring to be provided with pivotable guide vanes. By pivoting the guide vanes and with a swivel angle adapted to the respective requirements can be fixed, there is a possibility that Flow direction of the grinding chamber through the blade ring to optimize supplied fluids or carrier gas and the Flow direction of the two-phase mixture from the fluid and to influence the regrind particles in the grinding visible area of the mill. The inventive optimization of the grinding and Visual processes of a mill via a variable guide blade inclination is without a costly expansion of a Bucket ring and installation of a new bucket ring with changed bucket inclination possible.

The guide vanes are expedient with their pivot axis on the outer ring or an outer jacket of the blade ring pivotally attached and can be via a Mechanism accessible from the outside. It is therefore no interruption of the mill operation necessary to change the direction of flow via a changed inclination of the guide vanes of the fluid and the fluid-regrind mixture to change.

It is advantageous that the guide blades of the blade ring, which is an outer shell or outer ring and one inner jacket or an inner ring or an outer ring and have an outer surface of the grinding bowl as the inner ring can be pivoted in a swivel range, which from a swivel angle α of about 30 ° to 150 ° is formed. The swivel angle α is one Horizontal related, which by the pivot axis of the Guide vanes is placed and parallel to the associated one Flow surface of the blade ring runs.

Through an inclination adjustment with a swivel angle in the Range from about 30 ° to about 150 ° or from 30 ° to 90 ° or 90 to 150 °, there is Possibility that the fluid flow is not only in one with the direction corresponding to the direction of rotation of the grinding bowl, but can also be forced in one direction which faces the direction of rotation of the grinding bowl is.

To influence the flow direction as completely as possible to achieve the fluid flow, it is advisable the outer jacket ring, hereinafter simplified as the outer ring referred to, and the inner jacket ring, hereinafter referred to as the "inner ring" to form such that the pivotable guide vanes with each adjustable Swivel angle as narrow a gap to the adjacent Form wall surfaces, in particular to the outer ring.

It is therefore advantageous if at least the outer ring in the swivel ranges of the individual guide vanes has a flat surface which is perpendicular to the guide vanes runs.

In a particularly preferred embodiment, the Bucket ring made of a variety of polygon segments, which are flat and not curved and one closed polygon (polygon). Such one Polygon blade ring in segment shape is compared to the well-known shovel rings, which only after their manufacture into individual segments and on site be reassembled, and also compared to that segmented blade ring with horizontally adjustable Outer ring segments much more advantageous in terms of Manufacture, transport, assembly and especially in relation on influencing the grinding and vision processes with the help pivotable guide vanes for changing the flow direction of the fluid-regrind mixture.

The polygon blade ring in segment shape has one in particular advantageous training a polygonal outer ring with a variety of outer polygon segments, whose Number and dimensioning according to the size of the Blade ring or the mill and depending on the Length and the predefinable pivot angle of the pivotable Guide vanes can be determined.

In particular, the pivot angle determines one or several guide vanes in the area of an outer polygon segment its minimum length, the length of the outer polygon segments the tendons or the connecting lines between those lying on a circle surrounding the polyon Points of the polygon. It will be an inexpensive one Production of the blade ring designed as a polygon or the outer ring in segment form, because the Outside polygon segments and possibly also inside polygon segments from flat sheets and through a multiple cut can be produced.

Another advantage is the fact that the site ready-to-assemble blade polygon segments can be, with an outer polygon segment with one or more pivotable guide vanes an outer polygon segment and associated inner polygon segment with one or more, pivotable on both segments fixed guide vane (s) can exist.

The pivotable guide vanes can be different have arranged pivot axes and corresponding to the Arrangement of the swivel axis in the area of a blade ring segment be attached. Are particularly advantageous Guide vanes with a centrally arranged swivel axis. This swivel or adjustment axis runs vertically to the flow areas of the outer ring segments and inner ring segments, that is, with inclined outer ring segments and inner ring segments inclined accordingly. The Swivel axis can also be in the area of a lower edge of the Guide vanes, which are also compared as gas inlet edge to an upper edge of the blade or a gas outlet edge can be designated. Basically can by training the gas inlet or An additional gas outlet edge of the guide vanes Influencing the flow. Especially with one The swivel axis on the lower guide vane edge is a rounded one or streamlined training advantageous, these continue in the shape of the guide vanes can. The guide vanes can therefore be flat or also be curved.

There is an adjustment mechanism for adjusting the inclination of the guide vanes advantageous, which is an adjustment outside of the mill housing and during mill operation. The adjustment mechanism can be used for a guide vane, for several arranged on a blade polygon segment Guide vanes, for groups of guide vanes on several Blade polygon segments or for all guide blades be provided and as an individual, in groups or an adjustment of all guide vanes his.

In addition, it is useful to guide the vanes in their respective Tilt lock to prevent unwanted adjustment or to avoid "flapping" of the guide vanes. For example, a clamp can also be used for locking Latching device on the guide vanes and advantageously be provided on the outer wall of the mill housing. It is particularly useful to lock the guide vanes in to integrate the adjustment device.

The adjustment of the guide vanes can be particularly easy simple training manually and either from the inside of the mill or from outside the mill. An automatic Setting is with mechanical, known per se, electrical and hydraulic elements possible. Known to transmit the adjustment movements Drives, for example gear drives, crank drives, Coupling linkage with spherical bearings, in particular ball joints, be used.

Fig. 1

einen Ausschnitt einer ersten Ausbildungsvariante eines erfindungsgemäßen Polygon-Schaufelkranzes in Segmentform in perspektivischer Darstellung;

Fig. 2

einen Ausschnitt einer zweiten Ausbildungsvariante eines erfindungsgemäßen Polygon-Schaufelkranzes in Segmentform in perspektivischer Darstellung;

Fig. 3

einen Längsschnitt durch eine Luftstrom-Wälzmühle im Bereich eines Polygon-Schaufelkranzes der zweiten Ausbildungsvariante;

Fig. 4

eine Draufsicht auf einen erfindungsgemäßen Polygon-Schaufelkranz in Segmentform mit verschwenkbaren Leitschaufeln;

Fig. 5

einen vergrößerten Ausschnitt des Schaufelkranzes nach Fig. 4;

Fig. 6

eine Ansicht eines Schaufelkranz-Polygonsegmentes des Schaufelkranzes nach Fig. 5;

Fig. 7

eine Draufsicht auf ein Schaufelkranz-Polygonsegment des Schaufelkranzes nach Fig. 5;

Fig. 8

eine Ansicht eines Schaufelkranz-Polygonsegmentes nach Pfeil VIII in Fig. 5;

Fig. 9

einen Längsschnitt durch eine Luftstrom-Wälzmühle mit einem Schaufelkranz-Polygonsegment und Verstellmechanismus für eine Leitschaufel und

Fig. 10

eine Darstellung analog zur Fig. 9 mit einer zweiten Variante eines Versteilmechanismus für die verschwenkbaren Leitschaufeln.

The invention is described below with reference to a drawing. This shows in a highly schematic representation:

Fig. 1

a detail of a first embodiment of a polygon blade ring according to the invention in segment form in a perspective view;

Fig. 2

a detail of a second embodiment of a polygon blade ring according to the invention in segment form in a perspective view;

Fig. 3

a longitudinal section through an airflow roller mill in the region of a polygon blade ring of the second embodiment;

Fig. 4

a plan view of a polygon blade ring according to the invention in segment shape with pivotable guide blades;

Fig. 5

an enlarged section of the blade ring according to Fig. 4;

Fig. 6

a view of a blade ring polygon segment of the blade ring according to Fig. 5;

Fig. 7

a plan view of a blade ring polygon segment of the blade ring according to FIG. 5;

Fig. 8

a view of a blade polygon segment according to arrow VIII in Fig. 5;

Fig. 9

a longitudinal section through an airflow roller mill with a blade ring polygon segment and adjustment mechanism for a guide vane and

Fig. 10

a representation analogous to FIG. 9 with a second variant of an adjusting mechanism for the pivotable guide vanes.

Figure 1 shows an example of a first training variant of a polygon blade ring 1 in segment form in one partial perspective view. The polygon blade ring 1 has an outer jacket or outer ring 2, an inner jacket or inner ring 3 and guide vanes 4, which between the outer ring 2 and the Inner ring 3 arranged radially and around a centrally formed Pivot axis 25 are pivotable.

The polygonal blade ring 1 consists of a large number of connected, connected polygon segments 10, which each have flat and opposing outer polygon segments 5 and inner polygon segments 6 and a pivotable Have guide vane 4. There can also be two three or more pivotable guide vanes 4 on one Polygon segment 10 may be attached. The direction of inclination of the Guide vanes 4 is only in Fig. 1 and the other figures exemplary and can also be set in the opposite direction. In a plan view, the segmented blade ring 1 is a closed polygon, which due to the large number the polygon segments 10 almost forms a circle (see Fig. 4). The inner polygon segments 6 are in the example 1 approximately parallel to those inclined inwards Outside polygon segments 5 arranged, and the radially in between arranged guide vanes 4 form flow channels 14. The angle of inclination β of the outer polygon segments 5 can be, for example, about 15 °. The opposite flat surfaces of the inner polygon segments 6 and the outer polygon segments 5 ensure adjustment one or more guide vanes 4 and a very small one Gap between the side edges 24, 34 and Outside and inside polygon segments 5, 6 (see Fig. 3).

For reasons of clarity, the Pivot axes 25 of the guide vanes 4 are only shown schematically. It can be seen that the pivot axes 25 accordingly the angle of inclination β is not completely horizontal. From the arrangement of the guide vanes 4 in the area of Blade segments 10, which are also called polygon segments can be designated, it follows that the pivot axis 25 is formed approximately in the center of the guide vanes 4 and the guide vanes 4 with the pivot axis 25 almost in the middle in the inner polygon segments 6 and outer polygon segments 5 are guided and in a swivel range of about Swiveled 30 ° to 150 ° and fixed can.

The outer polygon segments 5 can with a cover and Be provided attachment, which segments complementary can be formed and then has individual elements 12 or integrated into the outer polygon segments 5 can be.

Figures 2 and 3 show a second variant a segmented polygon blade ring 1 with pivotable Guide vanes 4. The vane ring polygon segments 10 each have an outer polygon segment 5 and a pivotable guide vane 4. A polygonal Inner ring is not provided for in this training variant. The function of the inner ring 3 takes over an outer wall surface 7 of the grinding bowl 8, which is cylindrical is (Fig. 3).

The guide vanes 4 are flat and with a Swivel axis 25 on a lower guide vane edge 26 Mistake. The guide vanes 4 are about the pivot axis 25 swiveling in a swivel range and with one Swivel angle α can be fixed from approximately 30 ° to 150 °. The arrangement and dimensioning of a guide vane 4 on an outer polygon segment 5 and its dimensions are adapted to the possible swivel angle α, so that an unimpeded adjustment and a small distance between a guide vane 4 and the outer polygon segment 5 and the outer wall surface 7 of the grinding bowl 8 are guaranteed.

Figure 2 shows that several vanes 4 on one Outside polygon segment 5 can be arranged. Moreover can the guide vanes 4 with pivot axes 25 on one upper vane edge 27 almost "hanging" on the Outside polygon segments 5 fixed and positioned in this way be that the required pivoting is possible. The The direction of inclination of the guide vanes can also be opposite , i.e. the swivel angle α is approximately 90 to 150 ° be.

Figure 3 shows "on the fly" on the segmented analog to FIG polygonal outer ring 2 attached guide vanes 4. The same features have identical reference numerals. The guide vanes 4 are on a pivot axis 25 lower vane edge 26 pivotable. The pivot axis 25 is led to the outside and can in the area of Mill housing 11 manually or automatically (not shown) be operated. A clamping device 29 is on the outer wall of the mill housing 11 arranged and prevented a "flutter" and an unwanted adjustment of the Guide vanes 4. The clamping device 29 is used for locking and is one of the possible locking devices, which expediently in the adjustment devices should be integrated (not shown).

The asymmetrical formation of the guide vane 4 in the in Fig. 3 results from that with an inclination angle β arranged attachment of the outer polygon segments 5 on the mill housing 11 via elements 12 and out the cylindrical outer surface 7 of the grinding bowl 8, which in this training variant of the blade ring 1 the Function of the inner ring 3 takes over, as well as the perpendicular to the guide vanes 4 arranged on the outer polygon segments 5. The guide vanes 4 are sealed with their side edges 24 arranged adjacent to the outer surface 7 of the grinding bowl 8. An outward side edge 34 extends complementary to the inclination of the outer ring segments 5 and upper vane edge 27 is arranged approximately horizontally. The lower guide vane edge 26 with the pivot axis 25 runs obliquely inwards and ensures a particularly easy adjustment. Above the outer polygon segments 5 guide surfaces 13 are arranged, which are the flow surfaces extend the outer polygon segments 5 upwards, an angle deviating from β is also selected can be. This turns a fluid flow from a Air duct 17 away from the mill housing and in the direction Mill center 28 (Fig. 4) steered.

4 is a highly schematic representation a polygon vane ring 1 in segment shape with pivotable Guide vanes 4 on a large number of outer polygon segments 5 shown. The illustration shows that by the variety of polygon segments 5 a relative slight deviation from the circular design of the Mill housing 11 is made. This deviation is in Fig. 5, which according to a section of the polygon blade ring 1 Fig. 4 shows in an enlarged view, visible.

Fig. 6 shows a view, Fig. 7 is a plan view according to 5 and 8 are a rear view of an example for a blade polygon segment 10, which is an outer polygon segment 5 and a pivotable guide vane 4 with has a lower pivot axis 25. It becomes clear that the guide vanes 4 approximately diagonally on an outer polygon segment 5 arranged and for an optimal deflection of the Fluid flow are extended.

7 and 8, a guide vane 4, which with its lower pivot axis 25 in a lower, right-hand side Area of the outer polygon segment 5 is attached, in the range of a swivel angle α of approximately 30 to 90 ° be pivoted. When the pivot axis 25 in The lower, left-hand area would be the guide vane 4 turned on and the fluid flow would be from a Fluid channel 17 (FIG. 3) in the opposite direction, i.e. clockwise, redirect. Figure 8 illustrates that the guide vanes 4 advantageously also in the middle the outer polygon segments 5 and / or with a central one Swivel axis (not shown) and in both directions can be arranged pivotably.

FIGS. 9 and 10 show adjustment mechanisms for pivotable ones Guide vanes 4, which are actuated from the outside can. The adjustment device shown schematically in FIG. 9 31 is manually operable and has a Adjustment element 32, which through a guide opening of the mill housing 11 is guided and for non-positive Engagement in the pivot axis 25 of the guide vanes 4 is formed is. A locking device 32 ensures a secure fixation of the inclined guide vanes 4.

Figure 10 shows a transmission device 30 for mechanical Swiveling the guide vanes 4.

Claims (21)

Bucket ring for airflow roller mills, with an outer ring (2) and an inner ring (3), between which guide vanes (4) are arranged to form flow channels (14),
characterized by that the guide vanes (4) are arranged pivotably and can be fixed with a predeterminable pivot angle α. Blade ring according to claim 1,
characterized by that the pivotable guide vanes (4) can be fixed in the region of a pivot axis (25) on the outer ring (2). Blade ring according to claim 1 or 2,
characterized by that the guide vanes (4) can be swiveled steplessly or with few steps in a swivel range which is formed by a swivel angle α of approximately + 30 ° to 90 ° and -30 ° to 90 ° or 30 ° to 150 °, based on a horizontal line. Blade ring according to one of the preceding claims,
characterized by that the outer ring (2) is at least in the pivoting areas of the individual guide vanes (4) flat and perpendicular to the guide vanes (4). Blade ring according to one of the preceding claims,
characterized by that the blade ring is designed as a polygon blade ring (1) in segment form, which has a plurality of polygon segments (10), each with one or more pivotable guide blades (4). Blade ring according to one of claims 1 to 5,
characterized by that the polygon blade ring (1) in segment form as polygon segments (10) outer polygon segments (5) with attached, pivotable guide vanes (4) and that the outer polygon segments (5), which are connected to the outer ring (2) , level and designed to receive the pivot axes (25) of the guide vanes (4). Blade ring according to claim 6,
characterized by that the pivot axes (25) of the guide vanes (4) are each formed on a lower guide vane edge (26) or on an upper guide vane edge (27) or between the lower (26) and upper guide vane edge (27). Blade ring according to one of claims 5 to 7,
characterized by that the outer polygon segments (5) are flat sheets and are arranged with an inclination angle β. Blade ring according to one of the preceding claims,
characterized by that the guide vanes (4) are flat or curved. Blade ring according to one of claims 5 to 9,
characterized by that the pivot axes (25) of the guide vanes (4) are arranged centrally or off-center on the outer polygon segments (5). Blade ring according to one of claims 5 to 10,
characterized by that the pivot axes (25) of the guide vanes (4) are guided through the outer polygon segments (5) and a mill housing (11) or an annular channel wall and can be actuated from the outside to adjust the inclination. Blade ring according to one of the preceding claims,
characterized by that the guide vanes (4) can be locked in a predeterminable swivel angle α. Blade ring according to claim 12,
characterized by that clamping devices (29) are provided on the outwardly directed pivot axes (25), which lock the guide vanes (4) at a predeterminable pivot angle α. Blade ring according to one of the preceding claims,
characterized by that the guide vanes (4) can be pivoted and locked individually, in groups or together. Blade ring according to one of the preceding claims,
characterized by that the inclination adjustment of the guide vanes (4) can be carried out manually or automatically. Blade ring according to claim 15,
characterized by that an automatic inclination adjustment of the guide vanes (4) takes place mechanically, electrically or hydraulically. Blade ring according to claim 15 or 16,
characterized by that with an automatic inclination adjustment of the guide vanes (4) transmission devices (30), for example gear drives, crank drives or coupling linkages, are provided. Blade ring according to one of the preceding claims,
characterized by that the inner ring (3) is formed by an outer surface (7) of the grinding bowl (8) and the guide vanes (4) have an inner edge (9) which is parallel and at a short distance from the outer surface (7) of the grinding bowl (8) is arranged. Blade ring according to one of claims 1 to 17,
characterized by that the inner ring (3) is polygonal and consists of a plurality of inner polygon segments (6), which are flat sheet metal blanks, arranged opposite the outer polygon segments (5) and designed to accommodate the pivot axes (25) of the guide vanes (4) are. Blade ring according to claim 19,
characterized by that a polygon segment (10) of the polygon blade ring (1) in segment form of an outer polygon segment (5), an inner polygon segment (6) and one or more pivotable on the outer polygon segment (5) and inner polygon segment (6 ) fixable guide vane (s) (4), the inclination of which can be carried out from the outside and / or inside. Blade ring according to one of claims 1 to 17,
characterized by that the inner ring (3) is at least in the swivel ranges of the individual guide vanes (4) flat and perpendicular to the guide vanes (4).

Images